Stabilization of halobutenes



- Patented May 15, 1 945 STABILIZATION OF'HALOBUTEN'ES Rupert 0. Morris, 'Berkeley, and Edward C.

shokal, Oakland, Calif., assignors to Shell Development Company, San Francisco, Calif., a corporation of Delaware No Drawing.

Application March 3, 1943, Serial No. 477,896

2 Claims. (01. zen- 52.5)

This invention relates to a method for pre venting or inhibiting the decomposition of the halobutenes which contain a halogen atom linked to an-unsaturated carbon atom under conditions beta dimeth'ylacrolein, methyl vinyl ketone,

' ethylidene I acetone (3-penten-2-one) allyl acetone (5-hexen-2-one) mesityl oxide, phorone, iurfural, the benzoquinones, the naphthoqui nones, etc. I

encountered during their. transportation and 6 The method of stabilizing halobutenes prostorage. The invention also pertains to the vided by the invention is applicable irrespective stabilized halobutene compositions resulting from of the type of container in which the liquid is the application of such method. packaged, but is especially valuable in connection The marked tendency of the halobutenes with the shipment and/or storage of these orwhich contain a'halogen atom linked to an un- 1 ganic halides in ierruginous containers. saturated carbon atom,- particularly 2chloro- The invention is applicable to the stabilization butene-2,- to undergo decomposition during shipof the halobutenes which contain a halogen atom ment and storage, particularly in the presence linked to an unsaturated carbon atom. The of smallamounts of water, has been long recogoleiinic linkage in the halobutene may be benized. While in general this tendency is most tween the first and second carbon atoms (1 or pronounced in metal containers, as copper or alpha position), or it may be between the second ierruginous containers, in many cases extensive and third carbon atoms (2 or beta position). The

- decomposition may occur in glass as well. The invention is of particular value and usefulness decomposition whether occurring in glass or in as applied to the stabilization of 2-chlorobutenemetal imparts undesirable characteristics as bad -2 and the other 2 -halobutenes wherein the oleodor and objectionable color to the packaged flnic'linkage is in the two position. Such haloliquid which adversely aflect its salability. In butenes may contain one or a plurality of halothe case of metal containers theproblem may be gen atoms linked to the unsaturated carbon atom two-fold since substantial corrosion of the walls or carbon atoms, and one or a plurality of haloof the container may result. I gen'atoms may also be linked to saturated car- The various inhibitors which have heretofore bon atoms. The halogen atom or atoms present been proposed to suppress the deterioration of in the halobutene may be fluorine, chlorine, 01181110 de ur Sh pm nt a d StOl'a e bromine or iodine, Representative halobutenes while in some instances fairly efiective are in' which-may be stabilized in accordance with the general unsuitable for the stabilization of the invention are: 2-chlorobutene-2, 2-bromohalobutenes which contain a halogen atom linked butene-2, 2-iodobutene-2, 1,2-dichlorobutene-2, to an unsaturated carbon atom either because 2,3-dichlorobutene-2, 2,3-dibromobutene-2, 1,2,3- ot the large quantity of inhibitor which must be trichlorobutene-2, 1,2,4-trichlorobutene-2, 2- added or because of difliculties encountered in chlorobutene-1,- 2-bromobutene-1, l-chlorobuparating the inhibitor, when necessary, after tene-l, 2,3-dich1orobutene-1, 1-bromobutene-l, it has served its purpose. z-iodobutene-l, 1,2-dichlorobutene-1 and 1,2,3-

It has now been found that-the deterioration trichlorobutene-l. oi the halobutenes which contain ahalogen atom Although the proportion or amount of inlinked to en un ra car n a m. an perhibitor which is added to suppress the decomtieulelly those. ch a 2-chl0r0buten -2, wher 40 position of the halobutenes according to the ini h O efln e linka i i the Z-DoSition, under vention and to produce the novel compositions Ordinary conditions of shipment and Storage, of matter encompassed thereby may vary within ay be e tiv ly suppr ss d y mixing t er wide limits, it is preferred to add the sniallest wi h a Small amount of eny om efiective amount. This is usually between about from the class consisting of un aturated al e- 0.01% and about 5%, depending inter alia upon hydesand ketones. The one Or more carbonyl the degreeof instability of the particular halide G p o h un hy r ketene being prepared for shipment or storage, the pee p o ed may compri P r o a i o o n a riod over which the halide must be preserved, alkyl chain. which may 0 ar ot e t c e and the partictnar inhibitor which is being used. to a cyclic a i a we t e icy lic o hetero- The present invention has been found especyclic ser es or mavcomp part o a c o-v cially useful .as a means or stabilizing 2-chloroy l 0r heteleeyelie Repr n iv butene-2, large amounts of which are produced xamples of sui ompoundsinclude l i as a byproduct during thesynthesis or butaet ne d hy methy r e hy e, phadiene from dichlorobutaneu 2-chlorobutene-2 is useful, for example, as an ingredient in paint re-- movers and as a degreasing and extraction solvent.

When it is first recovered or prepared 2-chlorov butene-2 usually is clear and substantially waterwhite, and it has a swe et odor and does not give ofi hydrogen chloride fumes. However, when stored for even a relatively short period of time in glasscontainers the liquidv develops a deep yellow color and has a sharp disagreeable oder.

Storage in ferruginous vcontainers displays its decomposition even more prominently, i. e., it becomes nearly black and a tarry deposit forms on the sides of the container.

The suitability of several of the inhibitors provided by the invention in the stabilization of 2- chlorobutene-2 is illustrated by the following examples, it being understood that the practice of the invention is not limited to the stabilization of this particular halobutene.

Example I 1% by volume of methyl vinyl ketone was added to a bottle of freshly prepared 2-chlorobutens-2. When the bottle was examined at the end of 4'7 days no discoloration had occurred.

5% by volume of acrolein was added to a bottle of freshly prepared 2-chlorobutene-2. There was no discoloration after 54 days.

Example II v by volume of methyl vinyl ketone was addiii ed to a bottle of 2-chlorobutene-2 in which a strip of drum iron had been immersed. At the end of two weeks the Gardner scale reading on the liquid was less than 1 and the strip was only very slightly afiected (on the Gardner scale No. 1 is water-white, No. 15 is dark 'brown).

Example 111 A standard one-gallon steel shipping drum was filled about to full of by-product 2-chlorobutene-2 to which had been added about 0.01% by weight of quinone. The drum was allowed to remain on the laboratory roof exposed to the elements for 10 months, at the end of which time examination was made of the container and its contents. The liquid poured from the drum absolutely clear and there was only a very light- 

